Telescopic rod antenna



Dec. 18, 1945. F. TELLANDER ETAL TELES COPIC ROD ANTENNA 1945 3 Sheets-Sheet 2 Filed May 15 Dec. 18, 1945. F. TELLANDER ETAL TELES GOPIC ROD ANTENNA Filed May 15, 1945 3 Sheets-Sheet 3 Patented Dec. 18, 1945 mnscorlc non ANTENNA Frederic Tellander, Franklin Park, and Otto E. Wagcnknecht, Chicago, Ill., assignors to Zenith Radio Corporation, Chicago, Ill., a corporation of Illinois Application May 15, 1943, Serial No. 491,088

top of the screw and, being resiliently pressed 34 Claims.

This invention relates to telescopic rod ontonnes and has for its principal object to provide an improved antenna of the type which will automatically project and retract at the desire oi the operator.

In accordance with our invention we provide a telescopic rod antenna constituted of a plurality of telescopic sections. The sections are provided with means whereby they are held against relative rotation in all their positions. All the actuated sections are provided with a nut at or adiacent their lower ends, which nuts are adapted to be engaged and actuated in turn by a screw which is rotatably mounted within the lower section.

\ The screw terminates somewhat above the bottom of the lowermost section and it is connected to a rod of lesser diameter which extends downwardly below the lowermost section and is driven in suitable manner in either direction, for example by means of a reversibl motor.

When the actuable sections are fully retracted, the nut of the uppermost actuable section is clear of the lower end of the screw and bears against it resiliently. At the end of the retracting operation the end of the screw cooperates with the nut of the uppermost actuable section to provide a clicking noise which indicates to the operator 7 that the antenna is fully retracted so that he should stop the motor. When the motor is started in the proper direction, the nut of the uppermost actuable section" threads onto the screw and the uppermost section is elevated.

To insure that only one section at a time shall be actuated outwardly, we prefer to provide between the second and third sections and between the third and fourth sections and so on, means providing friction of progressively greater degree. Thus, the first said friction means prevents the second actuable section from being carried up with the first actuable section until the first actuable section is projected to full extent relative to the second actuable section. When this occurs the nut of the second section is brought into engagement with the lower end of the screw and the friction means between the second and third sections is overcome and the second section is projected upwardly. The lower friction means, providing greater friction, maintain all the sections below the second actuable section in their initial position until the second section is fully proi ected. 'I'hereupon the third section is engaged by the screw and is forced outwardly and so on until the antenna is fully projected.

when th antenna is fully projected, the nut of the second section from the bottom engages the against the screw so as to be in readiness to be rethreaded upon the screw when the screw is reversely rotated. and choking noise is again provided to indicate to the operator that the projection of the antenna is complete and that he should turn off the motor.

Since a lower nut is brought into engagement with the lower end of the screw shortly before the next higher nut disengages the screw, it is preferred, in order to prevent any possibility of jamming, to provide a certain degree of freedom between the nuts, that is, a degree of freedom which enables the lowermost nut to remain stationary for a short period of time until it properly engages the rotating screw.

This degree of freedom is provided in one embodiment of our invention by allowing the nuts to move longitudinally with respect to their sections, springs being provided to maintain the nuts in a normal position on their sections. In another embodiment of our invention we mount the nuts rigidly on their sections and provide an extensible screw shaft to ensure proper engagement of the nuts therewith. In still another embodiment of our invention we provide resilient means between adjacent sections so as to permit slight displacement of the nuts at the time of engagement with the screw.

It will be understood that the same degree of freedom or resilience is effective when the nuts are engaged at the upper end for retraction of the antenna which engagement occurs before the next lowermost nut is disengaged by the screw.

The features of the present invention which "are believed to be novel are set forth with particularity in the appended claims. The present invention itself, both as to its organization and manner of operation, together with further objccts and advantages thereof may best be understood by references to the following description taken in connection with accompanying drawings in which:

Figure 1 is an elevational view of our antenna mounted in the cowl of an automobile, which cowl is shown in section;

Fig. 2 is a longitudinal section through one embodiment of our invention, the intermediate part of the antenna being omitted;

Fig. 3 is a sectional detail taken on the line 3-4 of Fig. 2;

Fig. 4 is a sectional detail taken on the line H of Fig. 2;

Fig. 5 is a sectional detail taken on the line 5-! of Fig. 2;

Fig. 6 shows an elevational view of a modified form of our antenna mounted on the exterior of a vehicle such as a tank and provided with a resilient mounting to enable the vehicle to pass beneath branches of trees and other overhead obstructions without injury to the antenna;

Fig. 7 is a fragmentary sectional detail of a modified form of our antenna employing a resilient screw;

Fig. 8 is a longitudinal section of another antenna embodying our invention; and

Fig. 9 is a diagrammatic view showing the manner in which our improved antenna may be mounted on the root of an automobile.

Referring to the drawings, and particularly to Figs. 1 to 5 inclusive, our improved collapsible rod antenna comprises a plurality of tubes in telescopic relation. The lowermost tube lli cooperates with an innertube I l which in turn cooperates with a still smaller tube [2. The tube I2 telescopically receives the tube It. These tubes are in the retracted condition of the antenna located around an inner screw il in the manner shown in Fla. 2.

The upper ends of the tubes III, II and I2 are provided with reduced necks i5 which provide frictional sliding support for the tubes ll, l2 and II, respectively. The tubes Ii, l2 and it are provided with enlarged lower ends it which are arranged to have a sliding lit in the major portions of the tubes l0, II and I2, respectively. The tube l has an enlarged end H which is received rigidly in a suitable support it.

In order to limit the projection of the tubes i I, I2 and I3, relative to the tubes it, ii and I2, respectively, the tubes ll, l2 and i3 are provided at elevated positions thereon with enlargements i9 which are arranged, in the extended condition of the antenna, to engage the shoulders provided by the necks ii. In the case of the tube II, the projection is is shown as the upper part of the enlarged lower end l6.

Each of the tubes ll, l2 and it carries at its lower end a nut 20 which is threaded operatively to receive the screw I 4. The screw it is carried on the upper end of a reduced unthreaded shaft 2| and when the antenna is fully retracted, as shown in Fig. 2, the nuts 20 are located below the threaded portion of the screw [4 with the nut 20 of the tube l3 in contact with this threaded portion.

The shaft 2| is supported by a double thrust bearing 22 mounted in the support It. Means are provided for preventing relative rotation between the tubes H], II, l2 and I3. For this purpose the main portions of the tubes II), II and I2 are provided with vertical flutes 23 (Figure and the enlarged portions it of the tubes ll, i2 and iii are each provided with corresponding vertical flutes 24 (Figure 4) in such manner that they receive first said flutes respectively.

The nuts 20 are provided with vertical recesses or flutes which receive the flutes of the enlarged portions it which carry the nuts, thus providing for limited relative longitudina] movement between each nut and the tube which carries it while preventing relative rotation between the nuts and the tubes.

In the case of tubes II and It, the nut 20 is forced resiliently downwardly by means of a coil spring 25. the lower end of which bears against the nut 20. The upper end of each spring 25 abuts against a washer 26 located within the enlarged portion l8 0! the tube.

In the case of the tube l3, the washer 26 bears against an annular shoulder i lwhich may suitably be rolled in the enlarged portion 20. In the case of the tube II, the washer 2| may suitably bear against a 0 spring 28 which has portions projecting through openings in the enlarged portion Ii (Figure 3) or the tube II.

The nut 20 of the tube i2 is resiliently supported by two coil springs 2! and 30 so that it is free to move in either direction relative to the tube i2. The coil spring 30 abuts against the lower end of the nut 20 oi. the tube l2 and against a, shoulder rolled on the lower end of the enlarged portion it of the tube II.

The coil spring 28 bears against the upper side of the nut 20 and against a collar ll slidably mounted in the enlarged portion it of the tube II. The collar II is adapted to make contact with a 6 spring 32 which extends through openings in the enlarged portion I6 oi the tube l2 in the same manner as the 0 spring 28 (Figure 3) extends through openings in the enlarged portion It of the tube H. The collar II is provided with an upwardly directed reduced sleeve portion II which is adapted to project upwardly through the c spring 32 and to engage the lower end of the enlarged portion of the tube It in the manner shown in Fig. 2.

When the antenna is fully retracted, as shown in Fig. 2, all the nuts 20 are located below the threaded portion of the screw I, the nut 20 of tube It bearing against the lower end of the threaded portion of the screw under the combined action of the springs 29 and ill which are compressed. It will readily be understood that when the screw it is rotated in the clockwise direction as viewed from above (assuming that it has a right-hand thread) it will pick up the nut 20 of the tube It and that tube will be projected outwardly relative to the other tubes until its nut 20 runs of! the upper end of the screw ll.

Means are provided to ensure that the other nuts 20 are not engaged by the threaded portion or the screw I 4 before the tube l3 has been projected to full extent relative to the tube l2 and likewise means are provided for ensuring full projection of the tube 12 before movement of the tube II. This object is attained by providing progressively increasing friction between tubes l3 and i2, between tubes i2 and H, and between tubes II and Ill, in that order. This friction is suitably attained by the provision and proper design of the c springs 32 and 28. When the tube i2 starts to move up, the 6 spring 32 carried by it engages the inner shoulder provided by the upper end of the enlarged portion it of the tube II and it is only when the tube I! is positively driven upwardly that the friction provided by the 6 spring 32 is overcome.

The 0 spring 28 provides still greater friction and it is only when the tube i2 is projected to full extent that the tube ll starts to move up. The 0 spring 28 is arranged to engage the inner shoulder provided by the upper end of the enlarged portion ll of the tube III.

The screw I4 is of such length that the nut 20 of the tube I2 is engaged by it before the nut 20 of the tube It clears the screw it and the nut 20 of the tube H is engaged before the nut 20 of the tube l2 clears the screw ll.

Assuming that the antenna is in the fully retracted condition as shown in Fig. 2 and that the screw it is driven in clockwise direction as viewed irom above. it being a righthand screw, the tube It is projected out of the tube l2. If the friction between the tubes I3 and i2 tends 1 ll. Consequently, the

by the screw it and becomes engaged thereby. upward movement of the to move the tube i2 up at the same time. the 6 spring 22 is brought into contact with the inner shoulder oi the enlarged portion II o! the tube II, and ii the tube Ii tends to move upwardly as a result of the upward movement of the tube II, the spring 28 is brought into engagement with the corresponding shoulder on the enlarged portion ll of the tube ll.

Consequently, only the tube I2 is proiected and this projection continues until the enlargement ll of the tube ll engages the inner shoulder provided by the neck ll of the tube i2.. Thereupon the tube i2 is positively drawn upwardly by the tube ii. The not 22 of the tube i2 is still engaged by the screw it and this engagement continues until the nut 20 oi the tube I2 is brought into engagement with the lower end of the screw screw ll threads into the nut 20 of the tube 12. the spring 20 permitting a slightly downward displacement 0! this nut 2| to enable its proper engagement with screw ll.

Both the nuts 20 01 the tubes l2 and 12 are in engagement with the screw I4 and as the rotation of the screw continues, both the tubes II and 12 are projected upwardly. Alter the nut 20 of the tube It runs oil the screw ll, the screw projects the ube i2 upwardly and the tube i2 is carried up with it owing to the frictional engagement between the tubes l2 and IS.

The projection of the tube I2 continues until its projection it engages the shoulder provided by the neck I5 of the tube ll. when this happens, the tube H is positively moved upwardly by the tube l2 and the nut 25 of the tube ii is brought into engagement with the lower end of the screw I4. In the event that this nut 20 is not presented correctly to the screw ll, the nut 20 oi. the tube l2 may move up slightly relative to the tube l2 against the action of the spring 29, thus permitting the screw ii to pick up the lowermost nut 20 on tube I l.

The nuts 2B 01 the tubes l2 and ii are thus driven together by the screw ll until the nut 20 of the tube 12 runs oi! the upper end of the screw it. Thereafter the tube ii is driven upwardly and the tubes 13 and i2 are carried upwardly owing to the frictional engagement between the tubes l3 and i2 and i2 and ii.

During the upward projection of the tube ii, the lower spring 25 is compressed slightly by the friction of the tube Ii with the tube in acting on one side of the spring 25 and the drive of the lowermost nut 20 by the screw i4 acting on the other side of the spring 25. Consequently, when the tube Ii is fully projected, the lower spring 25 is under some compression and as the screw ll continues to rotate, the lowermost nut 20 slips on the end of the thread at the upper end of the screw il in the manner which provides an audible signal that full extension of the antenna has been attained, and maintaining the nut 20 of tube i I ready for rethread on screw l4 when that screw is reversely rotated.

In order to retract the antenna, the screw I4 is rotated in the opposite direction and since the nut 20 of tube H is pressed downwardly towards the upper end of the screw by the lower spring 25, the nut 20 of the tube ii is engaged by the screw I4 and the tubes ll, l2 and I: are initially moved downwardly as a unit. Before the nut 20 of the tube ll clears the lower end oi. the screw it, the nut 25 of the tube l2 isbrought into engagement with the If there is a slight nut 20 0! the tube I2 upper end of the screwby the screw ll due to the fact that the threads on nut 20 of tube it are not exactly in cooperating relationship with the threads on the screw ll when such nut initially engages the screw, this 5 slight movement is permitted by compression or the spring 2| whereby such nut 22 may be threaded on the screw without jamming.

Shortly after the engagement of the nut 20 oi the tube 12 by the screw ll and subsequent threading thereon, the nut 2O 01' the tube ll clears the lower end 0! the screw ii and the 0 spring 2! is engaged by the lower end of the tube l2 to effect downward movement of the tube ll.

The nut 22 01' the tube i2 is moved downwardly by the screw ll but before it reaches the lower .end of the screw, the nut 20 of the tube i2 is engaged by the upper end of the screw. It the nut 20 01' the tube It is not properly presented to the upper end at the screw ior ready engagement, the nut 20 of the tube i2 continues to move downwardly slightly against the action 0! the spring 20 and moves tube downwardly, the nut 20 on tube ll moving slightly upward against gagement of nut 22 on tube II with screw ll is obtained whereby the latter nut is prevented from jamming. Thereafter the nut 20 oi the tube It is moved downwardly by the screw ll until it clears the lower end of the screw. Before doing so, the lower end of the tube It engages the sleeve 32 and the tubes l2 and II are positively carried down by the downward movement of the tube ll.

when the nut 20 of tube It clears the lower end of the screw ll, it is biased upwardly by the springs 29 and 32 which are under compression and consequently as the screw l4 continues to rotate, the nut 25 of the tube I2 is reciprocated upwardly and downwardly against the end of the thread of the screw ll, giving an audible signal which indicates that full retraction has been attained and maintaining the nut 20 of tube l3 ready to rethread on screw ll.

It will be understood that all the nuts 20 may be mounted in their sections similar to the mounting provided for the second nut from the bottom in Fig. 2, or the nuts may all be mounted with the aid of a single spring 25 as shown in the two extreme nuts oi Fig. 2. If only single springs are employed with all nuts 20, it is, in some cases, possible, by manual interference, to overload the motor because nuts may start to thread on screw ll so as to jam. If only the spring 25 is used on tube l2, and ii tube I3 is manually pressed down so as to fully compress spring 25 of this tube, then nuts 20 of tube i3 and i2 may jam, because no relative movement can take place between them. On the other hand, ii spring 30 is used, then even if spring 25 of tube I3 is fully compressed due to manual interference, spring 29 or 30 will yield to provide for relative movement between nuts 20 of tubes [3 and i2. With the double springs 29 and 30, the motor is not thus overloaded, since the com presslon of one spring is opposed by the compression of the other spring and the displacement of a nut supported by the double springs is not accompanied by an increase of compression as is the case with single springs.

Our improved antenna may be provided with a manually operable section or sections. Thus,

as shown in Fig. 2, We may mount on the upper end of the tube i3 through spring 21 a socket 3t which frictlonally receives a rod 25 one end of the action of upper spring 25 until proper enspring 31 being fastened in socket 84 and the other end of spring 31 being secured in socket 21 which, in turn. is secured on tube ii. The rod 36 carries at its upper end a knob II whereby it may be manually pulled out from the socket M. The screw Il may suitably be made hollow so that the rod 35 may be telescoped thereinto. The rod 3! and the socket N are provided with complementary shoulders to prevent complete withdrawal of the rod II from the socket 34.

Since the rod 35 will normally provide a very high antenna, it is preferred to provide a resilient mounting of the socket ll upon the tube ll. Thus, we may connect the socket 34 to the upper end of the tube ll by means of a closewound spring 31 rigidly connected to both the socket 34 and the socket 21 on tube ii.

Consequently, ii the rod 35 strikes a high obstruction, the spring 31 can flex to enable the antenna to pass under the obstruction without injury thereto. To enhance the action of the sprin 31, and keep it under compression with its coils flat together, we prefer to provide within it a coil spring 38 under considerable tension and having its ends secured to the socket 3i and t the tube l3.

The screw ll may suitably be driven by a reversible motor 3! which is connected thereto by means of an insulating coupling 40. Our improved antenna may be mounted in any suitable location and is particularly suitable for use on automotive vehicles. In Fig. 1 is shown the preferred manner of mounting the antenna for use on an automobile. The tube III is supported on the cow] 4! of the automobile by means of an insulating bushing 42. The lower end of the tube III is supported by means of an insulating bushing 43 on a bracket 44 carried by the vehicle adjacent the floor level. When this manner of mounting is employed, an insulating lead-in wire 45 is connected to an elevated position on the tube Ill and a grounded shield 48 is arranged around the portion of the tube Ill inside the vehicle.

In the embodiment of the invention shown in Fig. 7, the screw I I is constituted by a stout coil of wire which is rigidly mounted on a rod 48'. This rod is carried at the upper end of a smaller rod 2| which is driven in the manner described in connection with the last-described embodiment. The extremities of the coil M extend beyond the rod 46 so that these portions of the screw are relatively resilient. The nuts 20 in this embodiment are conformed to cooperate with the coil screw l4, and are rigidly mounted at the lower ends of their sections.

As shown in Fig. 7, the uppermost nut is in engagement with the lower end of the screw it when the antenna is fully retracted. This lower end is then slightly compressed. When the rod ii is driven in the proper direction, the uppermost nut 20 meshes with the screw II and the uppermost actuable section is consequently driven upwardly. The next two lowermost sections are held by the springs 28 in the same manner as in the first described embodiment, until the shoulder of the uppermost actuable section engages the corresponding shoulder of the next lowermost section and elevates that next lowermost upwardly into engagement with the screw it.

As in the previously described embodiment, the second nut engages the screw l4 before the first nut is disengaged, and so forth. At the time of the engagement oi the second nut of the screw it, the distance between the two nuts engaging the screw is determined by the location of the nuts and the shoulders on the sections. The resilience of the ends of the screw M provides such change of dimension as may be necessary (or the proper engagement oi the engaging nut. That is, the resiliency of the screw 40' permits a slight collapse of the resilient screw 40' to enable the end of the screw to have threaded thereon a cooperating nut without jamming. Such collapsing of the screw takes place when the nut is improperly presented to the screw either at its upper or lower ends.

In this embodiment of the invention the sections may be held against relative rotation as in the first described embodiment of the invention, but the sections may be provided with sulficient resistance to rotary movement to enable the nuts to be engaged and disengaged without providing flutes or other means for holding the sections against relative rotation.

In the embodiment of the invention shown in Fig. 8, the nuts 20 are rigidly mounted at the lower ends of the sections and springs 41 are provided between a shoulder 48 near the lower end 0! an upper section and a shoulder 40 near the upper end of the next lowermost section. It will readily be understood that when the nut or an upper section is near the upper end 01 the screw l4 and has carried the next lower nut into engagement with the lower end of the screw II. the spring 41 is compressed slightly until the lowermost nut starts threading on the screw. Likewise, during retraction of the antenna, an upper nut is brought into engagement with the upper end of the screw before the next lower nut is disengaged and the spring 41 is again slightly compressed until the upper nut starts onto the upper end 01' the screw. In this embodiment 01' the invention, a spring 50 is provided at the bottom of the lowermost section. When all the sections are retracted, the lower ends 01' the sections i3 and I! bear against the friction springs 28 of the sections l2 and II respectively, or rigid means carried by the sections lz'and ll respectively, and the lower end of the section II bears uppermost nut 20 to be forced gently against the lowermost end of the screw I! so that it can be engaged thereby when the motor is started in the proper direction. As in the first described embodiment, the sections may be held against relative rotation, for example by flutes in the major lengths of sections l2, II and II and engaging flutes in the enlarged portions of the sections l3, l2 and II, respectively, below the shoulders 48.

Our improved antenna may be mounted outside a vehicle, preferably on the root thereof. Thus, in Fig. 6, we have shown our antenna mounted on the sloping wall 01' a tank. The lowor section of the antenna is connected by a spring assembly 5|, which may preferably be of the same construction as that provided by the springs 31 and 38, upon an insulator 52 carried by a bracket 53 mounted on the wall 54 of the tank. In this embodiment the shaft 21 terminates immediately below the lower end of the lower section and is connected to a motor 55 by mean oi a flexible shaft 56 which extends upwardly through an opening in the insulator I2 and through the spring connection 5|. An insulating connection 51 connects the shaft 58 to the motor and the lead-in 58 or the antenna may be connected to the outer stationary portion of accuses J the flexible sum so. It will readily be understood that the actuation of the motor 55 in either direction will eifect a projection of the antenna or the retraction thereof. The spring connection ll enables the antenna to be moved past an overhanging obstruction without injury to the antenna. 7

\ Our improved antenna may be mounted in other suitable locations on an automotive vehicle. Thus. asshown in Fig. 9, we may mount the antenna on the roof of an automobile, preferably immediately above and behind the center of the windshield. For this purpose, we may employ a housing lill whch may suitably be of plastc material upon the roof of an automobile. The housing 60 may contain a motor iii which is connected by an insulatng connector 82 to a shaft I3 which projects out of the housing at the angle which the antenna is intended to occupy.

The lowermost section ID of the antenna is rigidly secured to the close wound spring 84 which is rigidly mounted on the housing Gil. Within the spring 64 is located a coaxial spring 65 under substantial tension and secured to the lower end of the section III and tothe housing 60. A flexible shaft 68 extends through the springs 84 and B5 and connects the shaft 63 to the shaft 2i which extends out of the lower end of the section III in the manner previously described. A lead-in wire 61 may be connected to the lower end of the section ill and it may pass through a suitable opening in the roof 68 of the automobile.

The motor 8i and the motors of the previously described embodiments may be connected to the battery of an automotive vehicle or to other source of electrical energy by means of a conductor 89. The conductor 69 is connected to a single-pole three-position switch ill whereby the line 89 may be connected to a line H or 12 connected to the motor 6| so as to drive the motor ii in one direction or the other direction. In the normal intermediate position of the switch Iii, no energy is supplied to the motor.. The motor may have a single return wire 13 which may suitably be grounded. The switch Til may be located on the instrument panel of an automobile or in other suitable position within the vehicle on which the antenna is mounted. 7

While particular embodiments of the present vention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects, and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

We claim:

i. In a telescopic antenna having a plurality of sections adapted for relative projection and retraction, in combination, a screw within the lowermost section, said screw having a lower end terminating above the lower end of said lowermost section, a nut carried on each section above the lowermost section, resilient means for urging the nut carried by the uppermost section against said lower end of the screw, whereby the nut is adapted to be rethreaded on the screw after it has been threaded ofl said screw and means for rotating said screw in one direction or the other to project or retract the nut carrying sections seriatim.

2. In a telescopic antenna having a plurality of sections adapted for relative projection and retraction, in combination, means for preventing relative rotation between said sections, a screw within the lowermost section, said screw having a lower end terminating above the lower end of said lowermost section, a nut carried on each section above the lowermost section, resilient means for urging the nut carried by the uppermost section against said lower end of the screw. whereby the nut is adapted to be rethreaded on the screw after it has been threaded off said screw and means for rotating said screw in one direction or the other to project or retract the nut carrying sections seriatim.

3. In a telescopic antenna having a plurality of sections adapted for relative projection and retraction, in combination, a screw within the lowermost section, said screw having a lower end terminating above the lower end of said lowermost section, a nut carried on each section above the lowermost section, engaging means on said sections whereby the upward movement of one section tends to move the next lower section upwardly, said nuts and screw being correlated so that the nut of said next lower section is brought into engagement with the lower end of the screw before the nut of said on section runs off the upper end of the screw, resilient means for urging the nut carried by the uppermost section against said lower end of the screw, whereby the nut is adapted to be rethreaded on the screw after it has been threaded off said screw and means for rotating said screw in one direction or the other to project or retract the nut carrying sections seriatim.

4. In a telescopic antenna having a plurality of sections adapted for relative projection and retraction, in combination, means for preventing relative rotation between said sections, a screw within the lowermost section, said screw having a lower end terminating above the lower end of said lowermost section, a nut carried on each section above the lowermost section, engaging means on said sections whereby the upward movement of one section tends to move the next lower section upwardly, said nuts and screw being correlated so that the nut of said next lower section is brought into engagement with the lower end of the screw before the nut of said one section runs off the upper end of the screw, resilient means for urging the nut carried by the uppermost section against said lower end of the screw, whereby the nut is adapted to be rethreaded on the screw after it has been threaded 01! said screw and means for rotating said screw in one direction or the other to project or retract the nut carrying sections seriatim.

5. In a telescopic antenna having a plurality of sections adapted for relative projection and retraction, in combination, a screw within the lowermost section, said screw having a lower end terminating above the lower end of said lowermost section, a nut carried on each section above the lowermost section, engaging means on said sections whereby the upward movement of one section tends to move the next lower section upwardly, said nuts and screw being correlated so that the nut of said next lower section is brought into engagement with the lower end of the screw before the nut of said one section runs of! the upper end of the screw, resilient means for urging the not carried by the uppermost section against said lower end of the screw, whereby the nut is adapted to be rethreaded on the screw after it has been threaded 01! said screw, resilient means permitting a slight longitudinal movement between a nut on said screw and an engaging nut at the time of its engagement whereby jamming of the engaging nut is prevented, and means for rotating said screw in one direction or the other to project or retract the nut carrying sections seriatim.

6. In a telescopic antenna. having a plurality of sections adapted for relative projection and retraction, in combination, means for preventing relative rotation between said sections, a screw within the lowermost section, said screw having a lower end terminating above the lower end of said lowermost section, a nut carried on each section above the lowermost section, engaging means on said sections whereby the upward movement of one section tends to move the next lower section upwardly, said nuts and screw being correlated so that the nut of said next lower section is brought into engagement with the lower end of the screw before the nut of said one section runs oil the upper end of the screw, resilient means permitting a slight longitudinal movement between a nut on said screw and an engaging nut at the time of its engagement whereby jamming of the engaging nut is prevented, and means for rotating said screw in one direction or the other to project or retract the nut-carrying sections seriatim.

'i. In a telescopic antenna having a plurality 01' sections adapted for relative projection and retraction, said sections having engaging means whereby a projecting upper section causes the next lower section to follow its projecting movement and a retracting lower section causes the next upper section to follow its retracting movement, a screw within the lowermost section, said screw having a lower end terminating above the lower end of said lowermost section, a nut carried by each section above last said section, resilient means for urging the nut carried by the uppermost section against said lower end of the screw, whereby the nut is adapted to be rethreaded on the screw after it has been threaded on said screw and means for rotating said screw in one direction or the other to project or retract the nut carrying sections out of or into the lowermost section.

8. In a telescopic antenna having a plurality of sections adapted for relative projection and retraction, said sections havin engaging means whereby a projecting upper section causes the next lower section to follow its projecting movement and a retracting lower section causes the next upper section to follow its retracting movement, interengaging means on said sections preventing relative rotary movement therebetween, a screw within the lowermost section, said screw having a lower end terminating above the lower end of said lowermost section, a nut carried by each section above last said section, means for rotating said screw in one direction or the other to project or retract the nut carrying sections out of or into the lowermost section, and means for biassing the nut adjacent the screw into contact therewith when all the nuts are disengaged by the screw.

9. In a telescopic antenna having a lower section and an upper section in telescopic relation, a screw within the lower section, a reversible mofor driving said screw in either direction, and a nut on said upper section adapted to be actuated by said screw, said nut being correlated with said screw.wh'ereby it is worked ofl the lower end of said screw when the motor is driven in retracting direction, and means for holding said nut in engagement with the end of said screw for reth'reading action when the screw is driven in a proper direction.

10. In a telescopic antenna having a lower section and an upper section in telescopic relation, a screw within the lower section, a reversible motor for driving said screw in either direction, a nut on said upper section adapted to be actuated by said screw, said nut being correlated with said screw whereby it is worked 01! the lower end of said screw when the motor is driven in retracting direction, and resilient means for biassing said nut against the lower end of said screw, whereby said nut is maintained in readiness against the lower end 01' said screw for rethreading thereon.

11. In a telescopic antenna having a lower section and an upper section in telescopic relation, a screw within the lower section, a reversible motor for driving said screw in either direction, and a nut on said upper section adapted to be actuated by said screw whereby it is worked oil the upper end of said screw when the motor is driven in the projecting direction, and means for holding said nut in engagement with the end of said screw for rethreading action when the screw is driven in a proper direction.

12. In a telescopic antenna having a lower section and an upper section in telescopic relation, a screw within the lower section, a reversibl motor for driving said screw in either direction, a nut carried by said upper section adapted to be actuated by said screw whereby it is worked off the upper end of said screw when the motor is driven in th rojecting direction, means for bringing said nut into contact with the upper end of said screw for retracting engagement therewith, and resilient means for urging the not carried by said upper section against said upper end or the screw, whereby the nut is adapted to be rethreaded on the screw after it has been threaded oi! said screw.

13. In a telescopic antenna having a lower section and an upper section in telescopic relation, a screw within the lower section, a reversible motor for driving said screw in either direction, a nut carried by said upper section adapted to be actuated by said screw whereby it is worked oiT the upper end or said screw when the motor is driven in the projecting direction, and resilient means for urging the nut carried by said upper section against said upper end of the screw, whereby the nut is adapted to be rethreaded on the screw after it has been threaded off said screw.

14. In a telescopic antenna having a plurality of sections adapted for relative projection and retraction, in combination, a screw within the lowermost section terminatin above the lower end thereof, a not carried on each section above last said section, means for holding said nuts against rotation on their sections while providing limited axial movement thereon, and spring means biassing said nuts to definite axial positions on their sections, and means for rotating said screw in one direction or the other to project or retract the nut carrying sections seriatim.

15. In a. telescopic antenna having a plurality of sections adapted for relative projection and retraction, in combination, means for preventing relative rotation between said sections, a screw within the lowermost section, said screw having a lower end terminating above the lower end of said lowermost section, a nut carried on each section above last said section, means for holding said nuts against rotation on their sections while providing limited axial movement thereon, and spring means biassing said nuts to definite axial positions on their sections, and means for rotating said screw in one direction or the other to project or retract the nut carrying sections seriatim.

16. In a telescopic antenna having a plurality of sections adapted for relative projection and retraction, a rotatable screw within the lowermost section adapted to be rotated in opposite directions to effect the projection and retraction, a base, a close wound coil spring connecting the lowermost section to said base to support the sections in desired direction, a tension coil spring within the first said coil spring connected to the lowermost section and to said base, a reversible motor below said springs having a shaft mounted with its axis of rotation substantially coaxial with the axis of rotation of said screw, and a flexible shaft extending through said springs, connecting said motor to said screw, said coil spring, flexible shaft, motor axis and screw axis being substantially coaxial, whereby the antenna assembly may be mounted compactly and yet be bent at said coil spring to pass obstruc' tions without interfering with the driving mechanism thereof.

17. In a telescopic antenna having a plurality of sections adapted for relative projection and retraction, in combination, a screw within the lowermost section, said screw having a lower end terminating above the lower end of said lowermost section, a nut carried on each section above last said section, means for rotating said screw in one direction or the other to Project or retract the'nut-carrying sections seriatim, said screw being of such length that the nuts run on at least one end of said screw during projection and retraction, means biasing at least one of said nuts against the end of said screw when said one nut runs off the end of the screw to produce an audible noise to indicate the relative positions of said sections, and a plurality of means providing friction between a plurality of nutcarrying sections and the sections immediately below them, said friction means being arranged to provide progressively increasing friction in the downward direction of the projected antenna.

18. In a telescopic antenna having a plurality of sections adapted for relative projection and retraction, in combination, means for reventin relative rotation between said sections, a screw within the lowermost section, said screw having a lower end terminating above the lower end of said lowermost section, a nut carried on each section above last said section, means for rotating said screw in one direction or the other to project or retract the nut-carrying sections seriatim, said screw being of such length that the nuts run oil at least one end of said screw dur-- ing projection and retraction, means biasing at least one of said nuts against the end of said screw when said one nut runs oil the end of the screw to produce an audible noise to indicate the relative positions of said sections, and a plurality of means providing friction between a plurality,

relative rotation between said sections, a screw within the lowermost section, said screw having a lower end terminating above the lower end of said lowermost section, a nut carried on each section above last said section, means for rotating said screw in one direction or the otherto project or retract the nut-carrying sections seriatim, said screw being of such length that the nuts run oil at least one end of said screw during projection and retraction, means biasing at least one of said nuts against the end of said screw when said one nut runs off the end oi the screw to produce an audible noise to indicate the relative positions of said sections, means on each pair of adjacent nut-carrying sections whereby the upward movement of the uppermost of a pair tends to move the next lower section upwardly when the nut of said uppermost sections of a pair approaches the upper end of the screw whereby the nut of said next lowermost section is brought into contact with the lower end of the screw, and a plurality of means providing friction between a plurality of nut-carrying sections and the sections immediately below them, said friction means being arranged to provide progressively increasing friction in the downward direction of the projected antenna.

20. In a telescopic antenna having a plurality of sections adapted for relative projection and retraction, in combination, means for preventins relative rotation between said sections, a screw within the lowermost section, said screw havin a lower end terminating above the lower end of said lowermost section, a nut carried on each section above last said section, means for rotatlng said screw in one direction or the other to project or retract the nut-carrying sections seriatim, said screw being of such length that the nuts run off both ends of said screw durin projection and retraction, means on each pair of adjacent nut-carrying sections whereby the upward movement of the uppermost of a pair tends to move the next lower section upwardly when the nut of said uppermost sections of a pair approaches the upper end of the screw whereby the nut of said next lowermost section is brought into contact with the lower end of the screw, a plurality of means providing friction between a plurality of nut-carrying sections and the sections immediately below them, said friction means bein arranged to provide progressively increasing friction in the downward direction of the projected antenna, and resilient means permitting a slight longitudinal movement between a nut on said screw and an engaging nut at the time of its engagement whereby jamming of the engaging nut is prevented.

21. In a telescopic antenna having a plurality of sections adapted for relative projection and retraction, in combination, means for preventing relative rotation between said sections, a screw within the lowermost section, said screw having a lower end terminating above the lower end of said lowermost section, a nut carried on each section above last said section, means for rotating said screw in one direction or the other to project or retract the nut-carrying sections serlatim, said screw being of such length that the nuts run off both ends of said screw during projection and retraction, said nuts being mounted in said sections in non-rotational axially movable manner, springs in said nut-carrying sections resiliently forcing the nuts downwardly to a definite position on their sections, and means limiting the upward projectionoi a nut-carrying section relative to the section therebeneath, said screw and sections being correlated so that in the fully projected condition the lowermost nut is blessed resiliently by its spring against the upper end oi the screw and said nut-carrying sections bein correlated so that the nut of the next uppermost section is brought resiliently into engagement with the upper end of the screw before the nut oi the next lower section runs oil the lower end oi the screw during retraction.

22. In a telescopic antenna having a plurality of sections adapted for relative projection and retraction, in combination, means for preventing relative rotation between said sections, a screw within the lowermost section, said screw having a lower end terminating above the lower end of said lowermost section, a nut carried on each section above last said section, means for rotating said screw in one direction or the other to project or retract the nut-carrying sections seriatim, said screw being of such length that the nuts run oil both ends of said screw during projection and retraction, said nuts being mounted in said sections in non-rotational axially movable manner, springs in said nut-carrying sections resiliently forcing the nuts downwardly to a definite position on their sections, means limiting the upward projection of a nut-carrying section relative to the section therebeneath, said screw and sections being correlated so that in the fully projected condition the lowermost nut is blessed resiliently by its spring against the upper end 01' the screw and said nut-carrying sections being correlated so that the nut of the next uppermost section is brought resiliently into engagement with the upper end of the screw before the nut of the next lower section runs off the lower end of the screw during retraction, and resilient means effective in the fully retracted condition of the antenna for biassing the uppermost nut against the lower end of the screw.

23. In a telescopic antenna having a plurality of sections adapted for relative projection and retraction, in combination, means for preventing relative rotation between said sections, a screw within the lowermost section, said screw having a lower end terminating above the lower end of said lowermost section, a nut carried on each section above last said section, means for rotating said screw in one direction or the other to project or retract the nut-carrying sections seriatim, said screw being of such length that the nuts run off both ends or said screw during projection and retraction, said nuts being mounted in said sections in non-rotational axially movable manner, springs in said nut-carrying sections resiliently forcing the nuts downwardly to a definite position on their sections, means limiting the upward projection of a nut-carrying section relative to the section therebeneath, said screw and sections being correlated so that in the fully projected condition the lowermost nut is biassed resiliently b its spring against the upper end of the screw and said nut-carrying sections being correlated so that the nut of the next uppermost section is brought resiliently into engagement with the upper end of the screw before the nut of the next lower section runs off the lower end of the screw during retraction, said sections being arranged to make contact at their lower ends in the fully retracted condition of the antenna, and resilient means on the sec-- ond nut-carrying section from the top of the antenna for forcing the uppermost nut-carrying section upwardly with its nut resiliently in engagement with the lower end of the screw.

24. In a telescopic antenna having a plurality of sections adapted for relative projection and retraction, in combination, means for preventing relative rotation between said sections, a screw within the lowermost section, said screw having a. lower end terminating above the lower end of said lowermost section, a nut carried on each section above last said section, means for rotating said screw in one direction or the other to project or retract the nut-carrying sections seriatim, said screw being or such length that the nuts run of! both ends or said screw during projection and retraction, said nuts being mounted in said sections in non-rotational axially movable manner, springs in said nut-carrying sections resiliently forcing the nuts downwardly to a definite position on their sections, resilient means in at least one nut-carrying section biassing its nut upwardly in a position to its downwardly acting spring whereby said nut is blessed resiliently in opposite directions to a, definite position on its section, means limiting the upward projection of a nut-carrying section relative to the section therebeneath, said screw and sections being correlated so that in the fully projected condition the lowermost nut is biassed resiliently by its spring against the upper end or the screw and said nut-carrying sections being correlated so that the nut of the next uppermost section is brought resiliently into engagement with the upper end of the screw before the nut oi the next lower section runs of! the lower end of the screw during retraction, and resilient means eilective in the fully retracted condition 01 the antenna for blessing the uppermost nut against the lower end of the screw.

25. In a telescopic antenna having a plurality of sections adapted for relative projection and retraction, in combination, means for preventing relative rotation between said sections, a resilient screw within the lowermost section, said screw having a lower and terminating above the lower end of said lowermost section, a nut rigidly carried on each section above the lowermost section, and means for rotating said screw in one direction or the other to project or retract the nutcarrying sections seriatim, each section being arranged to carry the nut or the adjacent section into engagement with the end of the screw before the nut of said each section runs off the screw, the resiliency of the screw providing a slight collapse of the screw to enable the end of the screw to engage the engaging nut without jamming.

26. In a telescopic antenna having a plurality of sections adapted for relative projection and retraction, in combination, means for preventing relative rotation between said sections, a resilient screw within the lowermost section, said screw having a lower end terminating above the lower end of said lowermost section, a nut rigidly carried on each section above the lowermost section, and means for rotating said screw in one direction or the other to project or retract the nutcarrying sections seriatim, each section being arranged to carr the nut of the adjacent section into engagement with the end of the screw before the nut of said each section runs oil the screw, the resiliency or the screw providing a slight collapse of the screw to enable the end of the screw to engage the engaging nut without jamming, said screw being of such length that it is collapsed slightly by the lowermost nut in fully projected condition and by the uppermost nut in fully retracted condition whereby retraction and projection are initiated immediately the screw is driven in proper direction.

27. In a telescopic antenna having a plurality of sections adapted for relative projection and retraction, in combination, means for preventing relative rotation between said sections, a screw within the lowermost section, said screw having a lower end terminating above the iowerend of said lowermost section, a nut rigidly carried on each section above the lowermost section, means for rotating said screw in one direction or the other to project or retract the nut-carrying sections seriatim, complementary shoulders on said sections limiting the upward projection thereof, springs between said complementary shoulders, the lowermost spring being arranged to bias the lowermost nut against the upper end of the screw in fully projected condition of the antenna, said shoulders and springs being arranged so that one moving section brings the nut or the next section into engagement with the end of the screw before the nut of said moving section clears the screw, said sections being arranged to make contact with their nuts clear of the lower end of the screw in retracted condition of the antenna, and spring means for forcing the movable sections upwardly so that the uppermost nut engages the lower end of the screw in said retracted condition.

28. In a telescopic antenna having a lowermost section and an upper movable section in telescopic relation, in combination, means for preventing relative rotation between said sections, a screw within the lowermost section, said screw having a lower end terminating above the lower end of said lowermost section, a nut carried on the movable section, means for rotating said screw in one direction or the other to proiect or retract the movable section, complementary shoulders on said sections limiting the upward projection of said upper movable section, a spring between said complementary shoulders, said screw being arranged so that the nut runs of! the end of the screw in the fully projected and fully retracted condition of said movable section, said spring being arranged to bias the nut against the upper end of the screw in fully projected condition 01' the antenna and spring means for blessing the nut upwardly against the lower end of the screw when said upper movable section is in retracted condition.

29. A retractible and extensible antenna comprising a support with a helical coil spring having one end of said coil spring secured to said support, and an extensible antenna assembly comprising a plurality of telescoping tubular members located one within the other, the outermost of said tubular members being secured to the other end of said spring. each of said tubular members except the outermost being provided, adjacent its lower end, with a threaded nut, and said tubular members being provided with means operating between them for preventing relative rotation between them, an elongated rotatable actuating member having an end portion provided with thread-like formations and havinga shank of reduced size, said thread-like formations being adapted to thread into said nuts, and said shank being adapted to be passed by said nuts, a rotatable, reversible motor having a shaft mounted with its axis of rotation substantially coaxial with the axis of rotation of said actuating member, a flexible shaft passing through said helical spring and connecting said motor shaft to said actuating member, whereby the antenna assembly may be mounted compactly and yet be bent at said helical spring to pass obstructions without interfering with the driving mechanism thereof.

30. In a telescopic antenna having a plurality of sections adapted for relative projection and retraction, in combination. a screw within the lowermost section, said screw having a lower end terminating above the lower end of said lowermost section, a nut carried on each section above the lowermost section, engaging means on said sections whereby the upward movement of one section tends to move the next lower section upwardly, said nuts and screw being correlated so that the not of said next lower section is brought into engagement with the lower end of the screw before the nut of said one section runs 01! the upper end of the screw, resilient means permit ting a slight longitudinal movement between a nut on said screw and an engaging nut at the time 01' its engagement, whereby jamming of the engaging nut is prevented, and means for rotating said screw in one direction or the other to project or retract the nut carrying sections seriatim.

31. In a telescopic antenna having a plurality of sections adapted for relative projection and retraction, in combination, a resilient screw within the lowermost section, said screw having a lower end terminating above the lower end of said lowermost section, a nut rigidly carried on each section above the lowermost section. and means for rotating said screw in one direction or the other to project or retract the nut carrying sections seriatim, each section being arranged to carry the nut of the adjacent section into engagement with the end of the screw before the nut of said each section runs off the screw, the resiliency of the screw permitting a slight collapse of the screw to enable the end of the screw to engage the engaging nut without jamming.

32. In a telescopic antenna having a plurality of sections adapted for relative projection and retraction, in combination, a screw within the lowermost section, said screw having a lower end terminating above the lower end of said lowermost section, a nut carried on each section above the lowermost section, means for rotating said screw in one direction or the other to project or retract the nut carrying sections seriatim, complementary shoulders on said sections limiting the upward projection thereof, springs'between said complementary shoulders, the lowermost spring being arranged to bias the'lowermost nut against the upper end of the screw in fully projected condition of the antenna, said shoulders and springs being arranged so that one moving section brings the nut of the next section into engagement with the end of the screw before the nut of said moving section clears the screw, said sections being arranged to make contact with their nuts clear of the lower end of the screw in retracted condition of the antenna, and spring means for forcing the movable sections upwardly so that the uppermost nut engages the lower end of the screw in said retracted condition.

33. A retractable and extensible antenna comprising a support with a helical coil spring having one end of said coil spring secured to said support, and an extensible antenna assembly comprising a plurality of telescoping tubular members located one within the other, the outermost of said tubular members being secured to the other end of said spring, each of said tubular members except the outermost being provided, adjacent its lower end, with a threaded nut, an elongated rotatable actuating member having an end portion provided with thread-like formations and having a shank of reduced size, said thread-like formations being adapted to thread into said nuts, a rotatable, reversible motor having a shaft mounted with its axis of rotation substantially coaxial with the axis of rotation of said actuating member, a flexible shaft passing through said helical spring and connecting said motor shaft to said actuating member, whereby the antenna assembly may be mounted compactly and yet be bent at said helical spring to pass obstructions without interfering with the driving mechanism thereof.

34. In an automobile having a roof and a windshield, a base member supported on said root directly above and midway between edges of the windshield, a telescopic antenna having a plurality of sections adapted for relative projection and retraction, a rotatable screw within the CERTIFICATE or CORRECTION.

Patent No. 2,391,202.

lowermost section adapted to be rotated in opposite directions to effect the projection and retraction, a close wound coil spring connecting the lowermost section to said base to support the sections in desired direction, a tension coil spring within the first said coil spring connected to the lowermost section and to said base, a reverslble motor below said springs and within said base, said motor having a rotatable shaft mounted with its axis of rotation substantially coaxial to the axis of rotation of said screw, and a, flexible shaft extending through said springs, connecting said motor shaft to said screw, said coil spring, flexible shaft, motor axis and screw axis being substantially coaxial whereby the antenna. assembly may be mounted on a small base and yet be bent at said coil spring to pass obstructions without interfering with the driving mechanism thereoif.

FREDERIC 'I'EILANDER.

O'I'IO E. WAGENKNECHT.

December 18 19l 5.

FREDERIC TELLANDER, ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follons: Page 2, second column, line 1, for "17" read --2T-- and second column, line 1 8, before after "lowermost" insert --section--;

the wordfluppermost insert --against flie spring 50.

page i first column, line 71,

The spring 50 causes the--; line 56, for "the" after "below" read --their--; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 26th day of February, A. n. 19i

(Seal) Leslie Frazer First Assistant Commissioner of Patents.

lower end, with a threaded nut, an elongated rotatable actuating member having an end portion provided with thread-like formations and having a shank of reduced size, said thread-like formations being adapted to thread into said nuts, a rotatable, reversible motor having a shaft mounted with its axis of rotation substantially coaxial with the axis of rotation of said actuating member, a flexible shaft passing through said helical spring and connecting said motor shaft to said actuating member, whereby the antenna assembly may be mounted compactly and yet be bent at said helical spring to pass obstructions without interfering with the driving mechanism thereof.

34. In an automobile having a roof and a windshield, a base member supported on said root directly above and midway between edges of the windshield, a telescopic antenna having a plurality of sections adapted for relative projection and retraction, a rotatable screw within the CERTIFICATE or CORRECTION.

Patent No. 2,391,202.

lowermost section adapted to be rotated in opposite directions to effect the projection and retraction, a close wound coil spring connecting the lowermost section to said base to support the sections in desired direction, a tension coil spring within the first said coil spring connected to the lowermost section and to said base, a reverslble motor below said springs and within said base, said motor having a rotatable shaft mounted with its axis of rotation substantially coaxial to the axis of rotation of said screw, and a, flexible shaft extending through said springs, connecting said motor shaft to said screw, said coil spring, flexible shaft, motor axis and screw axis being substantially coaxial whereby the antenna. assembly may be mounted on a small base and yet be bent at said coil spring to pass obstructions without interfering with the driving mechanism thereoif.

FREDERIC 'I'EILANDER.

O'I'IO E. WAGENKNECHT.

December 18 19l 5.

FREDERIC TELLANDER, ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follons: Page 2, second column, line 1, for "17" read --2T-- and second column, line 1 8, before after "lowermost" insert --section--;

the wordfluppermost insert --against flie spring 50.

page i first column, line 71,

The spring 50 causes the--; line 56, for "the" after "below" read --their--; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 26th day of February, A. n. 19b6,

(Seal) Leslie Frazer First Assistant Commissioner of Patents. 

